Data multiplex broadcasting method, data multiplex broadcasting system, receiving device, and recording device

ABSTRACT

An object of the present invention is to make it easy to recognize a start point and an end point of each music piece, when a plurality of music pieces are broadcasted. A music piece broadcast end information bit, which is reversed in its logic when a broadcast of a music piece ends, is newly added to information to be multiplexed and transmitted.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a data multiplex broadcastingsystem in which a plural kinds of data are multiplexed to betransmitted, and, in particular, to a data multiplex broadcasting systemsuitable for recognizing a start of broadcasting of a particular contenton the receiving side.

[0003] 2. Description of Related Art

[0004] In RDS (Radio Data System) and DAB (Digital Audio Broadcasting),programme-associated information or independent information ismultiplexed into audio information to be broadcasted. In RDS and DAB,audio information is sent being multiplexed with information called M/S(Music/Speech) flag which indicates whether the content of the audioinformation in question belongs to the category of music or the categoryof speech. On the receiving side, by referring to this flag, it is easyto recognize a point of time at which a broadcast of a piece of musicstarts after speech of a speaker in a broadcast programme, for example.In other words, by referring to this M/S flag, it is easy to record apiece of music broadcasted during a broadcast programme, onto an audiorecording-device such as an MD (Mini Disk) recorder from the beginningof the music piece in question.

[0005] In the case of RDS, when a programme is broadcasted, informationassociated to the contents of the programme is subjected to multiplexmodulation as RDS signal, and various services can be supplied to radiolisteners based on the RDS signal demodulated on the receiving side.

[0006] This RDS signal is obtained by using a subcarrier of 57 kHzoutside the frequency band of the FM-modulated wave, and by subjectingthis subcarrier to amplitude modulation with coded information datasignal associated to programme contents. This amplitude-modulatedsubcarrier is subjected to frequency modulation onto a main carrier andthen broadcasted.

[0007] In FIG. 14, RDS signal is repeatedly multiplexed and transmittedby groups each of which consists of 104 bits. Each group consists of 4blocks, and each block includes 26 bits. More particularly, the blockconsists of 16 bits of an information word and 10 bits of a check word.

[0008] Further, each group is classified into 16 types, Type 0 throughType 15, depending on its contents. In addition, for each type of group,one of two versions, A and B, is defined.

[0009] For example, 0A group is defined as basic tuning and switchinginformation, and includes a programme identification code (PI code), atraffic-information-programme identification code (TP code), programmestation code (PS code), and the like.

[0010] Information indicating whether contents of a broadcast belong tothe category of music or the category of speech is included in a secondblock of 0A group, 0B group and 15B group, and a fourth block of 15Bgroup. This information is called M/S (Music/Speech) flag, as describedabove. When the value of M/S flag is 0, it shows that the currentbroadcast contents belong to the category of speech, and, when its valueis 1, it shows the current broadcast contents belong to the category of“music”. M/S flag is assigned, for example, to 13th bit 521 of thesecond block in FIG. 14.

[0011] On the receiving side, by receiving and demodulating this RDSsignal, and by extracting M/S flag included in the 0A group, 0B group or15B group, it is possible to recognize whether the current broadcastcontents belong to the category of speech or to the category of music.Accordingly, by continuously monitoring this M/S flag, it is possible torecognize a point of time at which a broadcast of a piece of musicstarts after speech of a speaker in a broadcast programme, for example.Accordingly, it is possible to record apiece of music by an audiorecording device such as an MD player, from the beginning of the music.

[0012] On the other hand, in the case of DAB, it is also possible tomultiplex and transmit information similar to that in RDS. DAB isdigital audio broadcasting in which Orthogonal Frequency DivisionMultiplex system (OFDM system) is employed to carry out multiplexmodulation, and audio information is encoded in accordance with MPEGLayer II (International Standard system ISO/IEC 11172-3 Layer II).

[0013] In FIG. 15, an audio frame of DAB has a frame length of 24 ms,and is slightly different from a frame of MPEG. PAD (ProgrammeAssociated Data) included in this audio frame is for transmittinginformation associated with the programme. Utilizing this PAD, it ispossible to transmit information such as a programme name, a recordnumber, dynamic range control information, and the like. Further, PADincludes M/S (Music/Speech) flag that indicates whether broadcastcontents belong to the category of music or the category of speech.

[0014] Accordingly, in the case of DAB, by extracting PAD included in anaudio frame and referring to the content of M/S flag included in PAD, onthe receiving side, it is also possible to recognize a point of time atwhich a broadcast of a piece of music starts after speech of a speaker,for example, similarly to RDS. Thus, it is possible to record a piece ofmusic from the beginning by an audio recording device such as an MDplayer.

SUMMARY OF THE INVENTION

[0015] As described above, M/S flag indicates whether broadcast contentson the air belong to the category of music or the category of speech. Inother words, it is a flag showing a category of broadcast contents onthe air. However, use of M/S flag causes following problems in recordcontrol in an audio recording device such as an MD player.

[0016] Namely, when a plurality of music pieces are successivelybroadcasted, and it is desired to record a particular music piece out ofthese music pieces, the record control using M/S flag is not applicableto that situation. Accordingly, an operator must start a recordingoperation on the audio recording device in a timing synchronized a pointof time at which that particular piece of music is actually started tobe broadcasted. On that occasion, if the recording operation deviatesfrom the actual point of time when the broadcast of the music piece isstarted to be transmitted, it is probable that failure such as so-called“headless” may be caused.

[0017] Further, as described above, even if plural pieces of music areto be successively broadcasted immediately after speech in a broadcast,it is possible to utilize M/S flag for automatic start of recording insynchronization with start of broadcasting the first piece of music.However, it is impossible to automatically stop recording operation insynchronization with a start of broadcast of a music piece next to thefirst-broadcasted one. In other words, it is impossible to record onlythe first music piece. Accordingly, an operator must stop recording ofthe audio recording device in synchronization with an actual end ofbroadcasting of the music piece which is being recorded.

[0018] The present invention has been made taking the above situationinto consideration. An object of the present invention is to make itpossible to easily recognize divisional point of respective contentelements on the receiving side, even when the content elements of thesame category are successively broadcasted. In detail, an object of thepresent invention is to provide a data multiplex broadcasting method, aswitcher, a data multiplex transmitting device,.a receiving device, asystem controller, and a recording device which are able to support easyrecognition of divisional point of respective content elements on thereceiving side when the content elements of the same category aresuccessively broadcasted.

[0019] To attain the above object, in the data multiplex broadcastingmethod of the present invention, information which can specify a startor end of each content element is multiplexed to data expressingbroadcast contents and broadcasted when each content element of thebroadcast contents belongs to the same category.

[0020] In detail, in the case that broadcast data expressing broadcastcontents is formed of a plurality of successive element data, each ofwhich expresses a content element belonging to the same category, a codewhose state changes in synchronism with a start and/or end of eachelement data which is a constituent of said broadcast data ismultiplexed to said broadcast data to be broadcasted.

[0021] Or, in the case that broadcast data expressing broadcast contentsis formed of a plurality of successive element data, each of whichexpresses a content element belonging to the same category, a codeexpressing the number of element data which have been alreadytransmitted or have not been transmitted yet among the element datawhich constitute the broadcast data is multiplexed to said broadcastdata, in synchronism with a start or end of each of the element dataconstituting the broadcast data.

[0022] Or, a code, whose state changes in synchronism with switching ofinput sources of broadcast data expressing broadcast contents, ismultiplexed to said broadcast data to be broadcasted.

[0023] Further, to attain the above objects, a switcher of the presentinvention generates information that can specify switching of inputlines, i.e., switching of the content elements, in the case that theinput lines are switched thereby to include a plurality of contentelements into broadcast data expressing broadcast contents.

[0024] In detail, the switcher comprises: an input interface means forreceiving element data through a plurality of lines; a line selectionmeans for selecting element data of some one line out of the elementdata received by said input interface means through a plurality of linesand for generating a code when the selected line is changed, said codechanging its state in synchronism with said change of the selected line;and an output interface means for transmitting the element data selectedby and the code generated by said line selection means.

[0025] Further, to attain the above objects, a source controller of thepresent invention generates information that can specify switching ofthe information output devices, i.e., switching of the content elements,when a plurality of information output devices are controlled in theirstarts of output thereby to include a plurality of content elements intobroadcast data expressing broadcast contents.

[0026] In detail, the source controller comprises: a control means forcontrolling a plurality of information output devices, at leastconcerning their starting of output; a switching means for selectingsome one out of said plurality of information output devices; and asignal generating means for outputting a signal whose state changes insynchronism with a point of time at which said switching means switchesthe information output device to be selected.

[0027] Or, the source controller comprises: a control means forcontrolling a plurality of information output devices, at leastconcerning their starting of output; a switching means for selectingsome one out of said plurality of information output devices; and asignal generating means for deciding a content of associated informationassociated to information of a content element outputted by theinformation output device after switched, said associated informationincluding a code whose state changes in synchronism with a point of timeof switching the information output device to be selected, and forgenerating a signal indicating said decided content.

[0028] Further, to attain the above objects, a data multiplex system ofthe present invention generates information that can specify switchingof the information output device performing output, i.e., switching ofcontent elements, and multiplexes said information into the broadcastdata to broadcast the multiplexed data, when a plurality of informationoutput devices are controlled concerning their respective starting ofoutput thereby to include a plurality of content elements into broadcastdata expressing broadcast contents.

[0029] In detail, the data multiplex system comprises: a plurality ofinformation output devices; the above-described source controller; aprogramme configuration information generating means for generatingprogramme configuration information in accordance with the contentindicated by the signal supplied from the source controller; an encodingmeans for receiving information of the content element outputted by theinformation output device selected by the source controller and forencoding the received information; a multiplexing means for multiplexingthe information of the content element encoded by the encoding means andthe programme configuration information generated by the programmeconfiguration information generating means, and for generating amultiplex signal; a modulating means for modulating the multiplex signalgenerated by the multiplexing means; and a transmitting means forbroadcasting the multiplex signal modulated by the modulating means.

[0030] Further, to attain the above objects, the receiving device of thepresent invention monitors information that can specify switching ofrespective content elements included in the broadcast data and that ismultiplexed to the multiplex signal broadcasted by the data multiplexsystem, so as to detect points at which respective content elements areswitched.

[0031] In detail, the receiving device comprises: an extracting meansfor extracting a music piece broadcast end bit and an M/S flagmultiplexed into the broadcast data, as the information that can specifyswitching of respective content elements included in the broadcast data,said music piece broadcast end bit being reversed in its logic insynchronism with an end of the music piece broadcasted, and the M/S flagindicating music or speech; and an outputting means for outputting asignal indicating a divisional point between music pieces in synchronismwith a point of time at which the music piece broadcast end bit isreversed in its logic, in a state that the M/S flag indicates music.

[0032] Or, the receiving device comprises: an extracting means forextracting an information bit indicating a number of remaining musicpieces to be broadcasted and an M/S flag indicating music or speech, theinformation bit and M/S flag being multiplexed into broadcast data, asinformation that can specify switching of respective content elementsincluded in the broadcast data; and a signal generating means forgenerating a signal that indicates a value indicated by the informationbit when the M/S flag indicates music.

[0033] Further, to attain the above-described objects, the systemcontroller of the present invention utilizes the points of switchingcontent elements (music pieces) detected by said receiving device, so asto make a recording device to record a desired content element.

[0034] In detail, the system controller comprises: an interface forreceiving operator's designation of an ordinal number corresponding to amusic piece to be recorded; and a control part for causing the recordingdevice to start to record when the receiving device detects a point ofstarting broadcast of the music piece corresponding to said designatedordinal number.

[0035] Further, to attain the above-described objects, the recordingdevice of the present invention can record only desired content elementsby monitoring the information that can specify switching of respectivecontent elements included in the broadcast data and is multiplexed inthe multiplex signal transmitted by the above-described data multiplexsystem, so as to detect the points of switching respective contentelements.

[0036] In detail, the recording device comprises: a recording means forrecording broadcast data; an interface means for receiving aninstruction to start recording; an extracting means for extractingbroadcast data expressing broadcast contents and a divisional pointsignal for contents element data expressing respective content elementsconstituting the broadcast data, from the multiplex signal received; abuffer memory means for storing said extracted broadcast data anddivisional point signal over a certain period; a detecting means fordetecting a point at which a state of the divisional point signal storedin the buffer memory means changes; and a transfer means for supplyingthe broadcast data stored in the buffer memory means when and after thestate of the detected divisional point signal changed, when theinstruction is received by the interface means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037]FIG. 1 is an explanatory view showing structure of PAD included inan audio frame of DAB;

[0038]FIG. 2 is an explanatory view showing data structure of RDSsignal, to which a first embodiment of the present invention is applied;

[0039]FIG. 3 is a block diagram showing a transmission system to whichthe first embodiment of the present invention is applied;

[0040]FIG. 4 is a time chart showing an example-of contents of M/S flagand ME flag in the case that a music piece A, a music piece B, and amusic piece C are successively broadcasted after speaker's speech in asound programme;

[0041]FIG. 5 is a block diagram showing a receiver to which the firstembodiment of the present invention is applied;

[0042]FIG. 6 is a system configuration showing a recording system towhich the first embodiment of the present invention is applied;

[0043]FIG. 7 is a flowchart showing processing for recording only aparticular piece of music out of plural pieces of music broadcasted incertain programme;

[0044]FIG. 8 is an explanatory view showing data structure of RDSsignal, to which a second embodiment of the present invention isapplied;

[0045]FIG. 9 is a block diagram showing a transmission system to whichthe second embodiment of the present invention is applied;

[0046]FIG. 10 is a time chart showing states of M/S flag and NMinformation, showing state change in the case that a music piece A, amusic piece B, and a music piece C are successively broadcasted afterspeaker's speech in a sound programme;

[0047]FIG. 11 is a block diagram showing a recording system to which thesecond embodiment of the present invention is applied;

[0048]FIG. 12 is a flowchart showing a procedure for recording aparticular piece of music out of plural pieces of music broadcasted incertain programme;

[0049]FIG. 13 is a block diagram showing a recording device to which thepresent invention is applied;

[0050]FIG. 14 is an explanatory view showing structure of datamultiplexed as RDS signal; and

[0051]FIG. 15 is an explanatory view showing structure of an audio frameof DAB.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] Now, embodiments of the present invention will be describedreferring to the drawings.

[0053] First, referring to FIGS. 1-6, there will be described a firstembodiment of the present invention.

[0054] In a data multiplex broadcasting system to which the presentembodiment is applied, information bits indicating divisional pointsbetween content elements constituting broadcast contents are multiplexedto broadcast data expressing the broadcast contents, to be broadcasted.These information bits may change their states in accordance with startsand ends of respective content elements, or may change their states atthe divisional points between the content elements.

[0055] In the following, description will be given mainly with respectto information bits that change their states in such a manner that theirbit logic is reversed at divisional points between music pieces when thecontent elements are pieces of music. Here, the content elements are notnecessarily restricted to music pieces, and may be some collection ofcontents which become elements constituting a programme. Further, thedivisional points are suitable as long as they are divisional points inthe time domain, and, for example, they may be timing for switchinginformation output devices that become sources of broadcast contents.

[0056] In one mode of the data multiplex broadcasting system, amusic-piece-broadcasting end information bit (Music End flag, referredto as “ME flag” in the following), whose logic is reversed whenbroadcast of music pieces is ended, is added to the information which ismultiplexed to be transmitted.

[0057] For example, to apply the present data multiplex broadcastingsystem to DAB, an undefined bit existing in a PAD domain in which M/Sflag is included may be assigned to ME flag. In detail, as shown in FIG.1, ME flag is defined at b1 bit, an undefined bit (Rfa; Reserved forFuture Addition), of F-PAD ext in which M/S flag is included.

[0058] Further, to apply the present data multiplex broadcasting systemto RDS, ME flag may be multiplexed and transmitted, being defined withinan undefined group such as the type 10 group, for example. In detail, asshown in FIG. 2, ME flag may be defined at 14th bit of the block 2 orthe block 4 in the type 10 group.

[0059] As described above, information bit (ME flag) indicating an endof each of the content elements such as each of the music pieces can bemultiplexed to an ordinary broadcast, i.e., broadcast data expressingbroadcast contents, to be broadcasted.

[0060] Accordingly, a receiver which is able to receive the informationmultiplexed to and transmitted with an ordinary broadcast can recognizea point of time when a broadcasted music piece ends, by demodulatingmultiplexed information and, thereafter, extracting the above-describedME flag and recognizing the content of ME flag. A point of time when thebroadcast contents are switched from speech to a music piece can bedetected from the above-mentioned M/S flag. In the case that pluralpieces of music are successively broadcasted, ME flag is utilized torecognize an end point of a music piece, and, at the same time, torecognize a start point of the next music piece to be broadcasted.

[0061] By transferring this information, via control bus, to an audiorecording device connected to the receiver, the audio recording devicecan recognize a point of time at which a broadcast of the music piece isstarted.

[0062] Thus, when a user prearranges recording of a music piece inadvance in a stage before start of broadcasting a music piece, forexample, in a stage that the music piece is introduced, it is possiblethat the audio recording device automatically starts recording at themoment that it recognizes the point of time at which the music piecerequested by the user starts to be broadcasted, and automaticallyfinishes the recording at the moment that it recognizes the point oftime at which the broadcast of the music piece ends.

[0063] Next, referring to FIG. 3, there will be described a transmissionsystem for this data multiplex broadcasting system. Although atransmission system applied to DAB is described here, it, of course, canalso be applied to other standards, such as RDS for example.

[0064] In FIG. 3, a transmission system of DAB comprises a sourcecontroller 101, a plurality of reproducers 102 serving as informationoutput devices (source players), a PAD generator 103, an audio encoder104, a channel encoder 105, a time interleaver 106, a multiplexer 107, amultiplex controller 108, an FIC generator 109, a frequency interleaver110, and an OFDM modulator 111.

[0065] The above-mentioned source controller 101 controls thereproducers 102 such as a CD player and an MD player depending onbroadcast contents, so as to output broadcast signal to the audioencoder 104, and decides the contents of PAD constructed depending onthe broadcast signal to transfer information to a PAD generator 103.

[0066] When the source controller 101 controls the reproducers 102 tochange a music piece to be broadcasted, the source controller 101transfers information indicating that the music piece is changed to thePAD generator 103. In response, the above-mentioned ME flag is reversedin its logic to build in PAD by the PAD generator 103. As a matter ofcourse, when the reproducers 102 are in an ordinary reproducing state,ME flag builds in PAD without being reversed in its logic.

[0067] Audio signal reproduced in the reproducers 102 is processed inthe audio encoder 104, the channel encoder 105, and the time interleaver106, and transferred to the multiplexer 107. Programme associatedinformation to be multiplexed to the audio signal is generated by thePAD generator 103, and inputted into the audio encoder 104 similarly tothe audio signal to be added to it. Further, programme associatedinformation passes through the multiplex controller 108 and might bemultiplexed to the audio signal according to its contents, but it isusually constructed as FIC (Fast Information Channel) in the FICgenerator 109. This FIC is added to the audio signal, and thereafter, issubjected to frequency interleave in the frequency interleaver 110, andis subject to OFDM modulation in the OFDM modulator 111 to be DABtransmission signal.

[0068] Next, referring to FIG. 4, there will be described an example ofcontents of M/S flag and ME flag in the case that three pieces of music,A, B and C are successively broadcasted after speaker's speech in a DABsound programme.

[0069] In DAB system, it is defined that M/S flag is “10” when broadcastcontents are speech and “01” for music. When M/S flag is “00”, itindicates that information of M/S flag is not being sent, and “11” isreserved for future change in DAB system. ME flag of the presentinvention has no meaning in its value itself. However, it is definedthat ME flag is reversed in its logic when a broadcast of a music pieceis ended and another music piece is broadcasted or broadcast contentsare changed to speech.

[0070] When speaker's speech is on the air, M/S flag is “10”, so thatthe broadcast contents can be recognized as speech. The logic of ME flaghas no meaning in itself, and is assumed to be “0” here.

[0071] When the speaker's speech ends and broadcast of the music piece Astarts, M/S flag changes from “10” to “01”, so that it is possible torecognize that the broadcast contents change to a music piece.

[0072] Further, when the music piece A is switched to the music piece B,ME flag is reversed from “0” to “1”. Thus, it is possible to recognizethat the broadcast of the music piece A ends, and that broadcast of themusic piece B starts since M/S flag remains “01”.

[0073] Further, when the music piece B is changed to the music piece C,ME flag is reversed from “1” to “0”. Accordingly, it is possible torecognize that the broadcast of the music piece B ends, and thatbroadcast of the music piece C starts since M/S flag remains “01”.

[0074] Further, when the broadcast of the music piece C ends, and thebroadcast contents returns to speech again, M/S flag changes from “01”to “10”, so that it is possible to recognize that the broadcast contentsbecomes speech. At the same time, ME flag is reversed from “0” to “1”,so that it is possible to recognize that the broadcast of the musicpiece C ends.

[0075] Next, referring to FIG. 5, there will be described a DABreceiver. In FIG. 5, the DAB receiver comprises an antenna 121, areceiving circuit (tuner) 122, an OFDM demodulator 123, a channeldecoder 124, an audio decoder 125, DAC (digital-analog converter) 126, acontroller 127, and a user interface 128.

[0076] DAB broadcast wave that arrives at the antenna 121 and isreceived by the receiving circuit 122 is demodulated in OFDM demodulator123, and, then, decoded in the channel decoder 124 to extract audiosignal. The extracted audio signal is decoded in the audio decoder 125and converted from digital audio signal to analog audio signal in DAC126.

[0077] The controller 127 detects a state of the user interface 128 andrecognizes contents of user operation, to control a series of theabove-described operation. Further, the controller 127 receives contentsof FIC decoded in the channel decoder 124 and contents of PAD decoded inthe audio decoder 125 from respective devices, and extracts programmeassociated information required. Thus, by extracting M/S flag includedin PAD, it is possible to recognize whether broadcast contents are musicor speech, and by extracting the above-mentioned ME flag, it is possibleto recognize that a broadcasted music piece has ended.

[0078] By extracting both M/S flag and ME flag, it is possible torecognize a start point and an end point of a music piece beingbroadcasted.

[0079] When the state of M/S flag changes from “10” to “01”, it showsthat broadcast contents change from speech to music, and, at the sametime, that broadcast of a music piece is started. Conversely, when itsstate changes from “01” to “10”, it shows that broadcast contents changefrom music to speech, and, at the same time, that broadcast of a musicpiece ends.

[0080] Accordingly, when M/S flag is kept “01” and the logic of ME flagis reversed, it shows that a music piece being broadcasted will end andbroadcast of another music piece will start. Accordingly, for aplurality of music pieces which are successively broadcasted, it ispossible to recognize a start point and an end point of broadcast ofeach music piece.

[0081] Next, referring to FIG. 6, there will be described a recordingsystem in the present embodiment. This recording system utilizes theabove-mentioned ME flag to be adapted for recording music piecesbroadcasted in DAB broadcasting.

[0082] In FIG. 6, the recording system comprises a DAB receiver 130, asystem controller 131, a recorder 132, and a control bus 133.

[0083] The DAB receiver 130 is for receiving DAB broadcasting.

[0084] The system controller 131 performs system control of therecording system.

[0085] As the recorder 132, an MD recorder using a magneto optical diskas a recording medium may be used, for example.

[0086] The control bus 133 is for controlling respective devices. Whenbroadcast wave received by the DAB receiver 130 is recorded by therecorder 132, operation of a user is directed to the system controller131, and the system controller 131 performs operation control such asstart and stop of recording for the recorder 132.

[0087] Here, referring to FIG. 7, there will be described a procedurefor recording a particular piece of music out of some pieces of music tobe broadcasted in certain programme.

[0088] First, DAB receiver 130 recognizes broadcast contents now on theair, by using M/S flag and ME flag (S1).

[0089] Information indicating the above-mentioned recognized broadcastcontents is transferred to the system controller 131 and the recorder132, through the control bus 133 (S2).

[0090] In the case that the recorder 132 is provided with some displaydevice, it is possible to display the broadcast contents now on the airon that display device (S3).

[0091] Here, it is assumed that a user wishes to record only music pieceB out of the broadcast contents illustrated in the example of FIG. 4.When an operation of record prearrangement of the music piece B iscarried out on the system controller 131 (S4), the system controller 131gives operating instructions to the recorder 132 depending on contentsof M/S flag and ME flag transferred from DAB receiver 130.

[0092] When M/S flag changes from “10” to “01” (S5) and is transferredthrough the control bus 133 (S6), the system controller 131 canrecognize that broadcast of the first music piece A has been started(S7).

[0093] Next, while M/S flag remains “01”, ME flag is reversed (S8) andtransferred through the control bus 133 (S9). By this, it is possible torecognize that the broadcast of the music piece A ends and,successively, broadcast of the music piece B is started (S10).

[0094] When the broadcast of the music piece B whose recording isprearranged is started, the system controller 131 instructs the recorder132 to start recording, through the control bus 133 (S11). The recorder132 receives the instruction from the system controller 131 and startsto record the music piece B (S12).

[0095] Next, when ME flag is reversed while M/S flag remains “01” (S13),and it is transferred through the control bus 133 (S14), it is possibleto recognize that the broadcast of the music piece B ends and,successively, broadcast of the music piece C starts (S15).

[0096] Since the broadcast of the music piece B whose recording wasprearranged has ended, the system controller 131 instructs the recorder132 to stop recording, through the control bus 133 (S16). On receivingthe instruction from the system controller 131, the recorder 132 stopsrecording of the music piece (S17).

[0097] In the case that a plurality of music pieces are broadcastedsuccessively, and only particular successive music pieces are wanted tobe recorded in the MD, it is, of course, possible to automaticallyrecognize the beginning and end of the particular successive musicpieces.

[0098] Next, referring to FIG. 1 and FIGS. 8-12, there will be describeda second embodiment of the present invention.

[0099] In the data multiplex broadcasting system of the presentembodiment, number-of-music-pieces information (Number of Music data,referred to as “NM data” in the following) that indicates the number ofmusic pieces successively broadcasted before next speech, is newly addedto the information multiplexed and transmitted.

[0100] A receiver that can receive the information multiplexed to andtransmitted with an ordinary broadcast receives the information andrecognizes change in the number of music pieces to be successivelybroadcasted before the next speech, and thereby can recognize an endtime of each of the music pieces to be broadcasted. A point of time atwhich speech is switched to music can be detected using theabove-mentioned M/S flag. In the case that a plurality of music piecesare successively broadcasted, it is possible to use the above-describedinformation to recognize a point of time at which a music piece endsand, at the same time, to recognize a point of time when broadcast ofthe next music piece is started. Further, it is possible to recognizehow many music pieces remain to be broadcasted.

[0101] By transferring this information to an audio recording deviceconnected to the receiver, through the control bus, the audio recordingdevice also can recognize a point of time when the broadcast of themusic pieces is started.

[0102] Accordingly, when a user prearranges recording of a music piecein a stage before start of broadcasting music pieces, for example, in astage that the music pieces are being introduced, it is possible thatthe audio recording device automatically starts recording at the momentthat it recognizes the point of time when the music piece starts to bebroadcasted, and automatically finishes the recording at the moment thatit recognizes the point of time when the broadcast of the music pieceends.

[0103] For example, as shown in FIG. 1, in F-PAD type “01” in the dataframe of DAB, 4 bits except for M/S flag may be defined as NM data.

[0104] Further, as shown in FIG. 8, the upper 16 bits of the block 3 inRDS may be defined as NM data.

[0105] Here, application of this information of the number of musicpieces is not limited to a remaining number. As a matter of course,information of a number of already broadcasted music pieces, i.e., anumber showing order of a currently-broadcasted music piece may bemultiplexed to be broadcasted.

[0106] Referring to FIG. 9, there will be described a transmissionsystem for applying the present data multiplex broadcasting system toDAB.

[0107] In FIG. 9, the transmission system comprises an audio encoder201, a channel encoder 202, a time interleaver 203, a multiplexer 204, amultiplex controller 205, an FIC (Fast Information Channel) generator206, a frequency interleaver 207, and an OFDM modulator 208.

[0108] An audio signal is processed through the audio encoder 201, thechannel encoder 202, the time interleaver 203, and transferred to themultiplexer 204. Programme associated information to be multiplexed to abroadcast passes through the multiplex controller 205, and is usuallyconstructed as FIC in the FIC generator 206, although it may bemultiplexed to the audio signal according to its contents. This FIC isadded to the audio signal, and thereafter, is subjected to frequencyinterleave in the frequency interleaver 207, and is subjected to OFDMmodulation in the OFDM modulator 208 to be DAB signal. Theabove-mentioned NM data is incorporated into FIC, and multiplexed to theDAB signal.

[0109] Next, referring to FIG. 10, there will be described contents ofM/S flag and NM data. Here, the contents of M/S flag and NM data aredescribed using an example in which three pieces of music, A, B, and Care successively broadcasted after speaker's speech in a sound programmeof DAB.

[0110] When the speaker's speech is on the air, M/S flag is “10”, andthe broadcast contents can be recognized as speech. NM data represents 3corresponding to the fact that three music pieces are to be broadcasted.

[0111] When the speaker's speech ends and the broadcast of the musicpiece A starts, M/S flag changes from “10” to “01”. Thus, it is possibleto recognize that the broadcast contents change to a music piece. NMdata becomes 2 to show that two music pieces remain.

[0112] Thereafter, when the music piece A is switched to the music pieceB, one music piece remains, and, thus, NM data changes from 2 to 1.Accordingly, it is possible to recognize that the broadcast of the musicpiece A ends, and, since M/S flag remains “01”, it is possible torecognize that broadcast of the music piece B is started.

[0113] Then, when the music piece B is switched to the music piece C, NMdata changes from 1 to 0 to indicate that the broadcast will return tospeech after the music piece C. Accordingly, it is possible to recognizethat the broadcast of the music piece B ends, and, at the same time,that broadcast of the music C starts since M/S flag remains “01”.

[0114] Further, when the broadcast of the music piece C ends and thebroadcast contents return to speech again, M/S flag changes from “01” to“10”. Accordingly, it is possible to recognize that the broadcastcontents become speech and, at the same time, the broadcast of the musicC ends.

[0115] Next, referring to FIG. 11, there will be described an example inwhich the NM data is applied to recording a music piece broadcasted inDAB broadcasting.

[0116] In FIG. 11, a recording system comprises a DAB receiver 210, arecorder 212, a system controller 211, and a control bus 213 forconnecting them.

[0117] The DAB receiver 210 is for receiving DAB broadcasting.

[0118] The system controller 211 is for performing system control of therecording system.

[0119] The recorder 212 is for recording broadcast contents received bythe DAB receiver 210. As the recorder 212, an MD recorder using amagneto optical disk as a recording medium may be used, for example.

[0120] The control bus 213 is for controlling respective devices.

[0121] When broadcast wave received by the DAB receiver 210 is recordedin the recorder 212, user operation is directed to the system controller211, and the system controller 211 gives operating instructions to therecorder 212.

[0122] Here, referring to FIG. 12, there will be described an example inwhich a particular music piece out of some pieces of music is to berecorded in the recorder 212.

[0123] First, from M/S flag and NM data, the DAB receiver 210 canrecognize what is the broadcast contents now on the air and canrecognize how many music pieces are to be successively broadcasted (S1).This information is transferred to the system controller 211 and therecorder 212 through the control bus 213 (S2). In the case that therecorder 212 is provided with some display device, it is possible todisplay the broadcast contents now on the air and how many music piecesare to be broadcasted on that display device (S3). The user canrecognize how many music pieces are to be broadcasted from now on,through that display device.

[0124] Here, there will be expressed a case that the user wishes torecord only the music piece B out of the broadcast contents illustratedin the example of FIG. 10. When prearrangement of recording the musicpiece is performed through the system controller 211 (S4), the systemcontroller 211 gives operating instructions to the recorder 212depending on the contents of M/S flag and NM data from the DAB receiver210.

[0125] When M/S flag changes from “10” to “01” and NM data changes from3 to 2 (S5), and this information is transferred through the control bus213 (S6), the system controller 211 can recognize the start of broadcastof the first music piece A out of three to be broadcasted (S7).

[0126] Next, when NM data changes from 2 to 1 while M/S flag remains“01” (S8), and it is transferred through the control bus 213 (S9), it ispossible to recognize that the broadcast of the music piece A ends and,successively, broadcast of the music piece B is started (S10).

[0127] Since the broadcast of the music piece B whose recording has beenprearranged is started, the system controller 211 instructs the recorder212 to start recording, through the control bus 213 (S11). On receivingthe instruction from the system controller 211, the recorder 212 startsto record (S12).

[0128] Next, when NM data changes from 1 to 0 while M/S flag remains“01” (S13) and this information is transferred through the control bus213 (S14), it is possible to recognize that the broadcast of the musicpiece B ends and, successively, broadcast of the music piece C isstarted (S15).

[0129] Since the broadcast of the music piece B whose recording has beenprearranged ends, the system controller 211 instructs the recorder 212to stop recording, through the control bus 213 (S16). On receiving theinstruction from the system controller 212, the recorder 212 stopsrecording (S17).

[0130] Here, it is obvious that, when a plurality of music pieces aresuccessively broadcasted, and only two or more successive music piecesout of the music pieces are recorded by the recorder, it is possible toautomatically recognize the beginning and end of the two or moresuccessive music pieces.

[0131] Next, referring to FIG. 13, there will be described a thirdembodiment of the present invention.

[0132] In FIG. 13, a recording device 350 comprises a buffer memory 351,a timing detector 352, an interface 353, a transfer control part 354, adata recorder 355, and a decoder 356.

[0133] The interface 353 is for receiving an instruction to startrecording.

[0134] The decoder 356 is for multiplex decoding of multiplex signal andsupplied thereto for extracting contents-expressing data and adivisional signal on the contents of the contents-expressing data fromthe received data multiplex signal. In the case that thecontents-expressing data and the divisional signal on the contents ofsaid contents-expressing data are supplied separately, it suffices thatthe decoder is provided with a function of decoding the data.

[0135] The buffer memory 351 is for storing the extractedcontents-expressing data and division signal over a certain period.

[0136] The timing detector 352 is for detecting a point of time at whicha state of the division signal stored in the buffer memory 351 changes.

[0137] The data recorder 355 is for recording the data.

[0138] The transfer control part 354 is for controlling data transferfrom the buffer memory 351 to the data recorder 355. When the interface353 receives an instruction of start of recording, the transfer controlpart 354 transfer the data stored in the buffer memory 351 since thepoint of time at which a state of the divisional signal changes, to thedata recorder 355, at that point of time being detected by the timingdetector 352.

[0139] By this, in the case that the buffer memory 351 includes a pointof time at which a state of the divisional signal changes, it ispossible to go back to that point and to start recording just from thatpoint of time.

[0140] Here, a display part may be provided for displaying a time periodobtained by subtracting a period elapsed from the detected point of timeat which the state of the divisional signal has been changed, from thecertain period for which the buffer can store the data. Using thisdisplay part, it is possible to display a residual quantity of thebuffer memory 351 from the divisional signal, i.e., a residual quantityor capacity of the buffer memory 351 which can be used for recordingfrom the past point of time at which a state of the divisional signalchanged.

[0141] The above description has been made mainly on the case that thepresent invention is applied to an audio broadcast. However, as a matterof course, the present invention is not restricted to an audiobroadcast, and can be applied to moving picture, data broadcasting, andthe like. For example, when applied to television broadcasting, it ispossible to record only a particular interval of pictures out of aseries of pictures successively broadcasted. Further, it is possible tomultiplex and broadcast divisional signal concerning a time domain forbroadcasting content elements which are expected to be recorded on thereceiving side, such as an access address relating to the programme, inparticular, application or reference address information in a programmeof mail-order sail or the like. Further, in the case that data such asstock quotations are broadcasted, the present invention can be appliedto selecting and recording data of a particular name or issue.

[0142] According to the present invention, a receiver able to receiveprogramme associated information or independent information multiplexedto an ordinary broadcast can recognize the number of content elementsbroadcasted in a broadcast programme, and can recognize a start pointand end point of broadcasting a particular content element.

[0143] In particular, in the case that music pieces are employed ascontent elements, it is possible to recognize the number of a series ofmusic pieces successively broadcasted, and to recognize start and endpoints of particular music piece out of the series of music pieces.

[0144] By this, in an acoustic system including an audio recordingdevice such as an MD recorder, it is possible to attain a function ofprearranging recording of a particular music piece to be broadcasted ina broadcast programme.

[0145] Further, when a plurality of music pieces successivelybroadcasted are recorded in an MD recorder, it is possible to recognizeintervals between the music pieces, and, thus, it is possible to attaina function of automatically separating a track.

[0146] Further, in a recording device to which the present invention isapplied, it is possible to go back to a point of time at which a stateof divisional signal on data contents changed to start to record justfrom that point of time.

What is claimed is:
 1. A method of data multiplex broadcasting, whichcomprises multiplexing data to be transmitted and a code that changesits state in synchronism with respective starts of content elementsexpressed by said data, and broadcasting said data and said code whichare multiplexed.
 2. A method of data multiplex broadcasting, whichcomprises: multiplexing data to be transmitted, a code that changes itsstate in synchronism with starts and ends of a series of contentelements expressed by said data, and a code that changes its state inaccordance with divisions between said content elements, andbroadcasting said data and said codes which are multiplexed.
 3. A methodof data multiplex broadcasting, which comprises: multiplexing data to betransmitted and a code expressing a number of content elements that havebeen transmitted out of a series of content elements expressed by saiddata, and broadcasting said data and said code which are multiplexed. 4.A method of data multiplex broadcasting, which comprises: multiplexingdata to be transmitted and a code expressing a number of contentelements that are not transmitted yet out of a series of contentelements expressed by said data, and broadcasting said data and saidcode which are multiplexed.
 5. The method of data multiplex broadcastingaccording to claim 3, wherein a code that changes its state inaccordance with starts and ends of said series of content elements isfurther multiplexed with said data.
 6. The method of data multiplexbroadcasting according to claim 4, wherein a code that changes its statein accordance with starts and ends of said series of content elements isfurther multiplexed with said data.
 7. A method of data multiplexbroadcasting, which comprises: multiplexing data expressing broadcastcontents and a code that changes its state in synchronism with a pointof time at which input sources becoming said broadcast contents areswitched, and broadcasting said data and said code.
 8. A switcher,comprising: an input interface means for receiving data through aplurality of lines; a line selection means for selecting data of someone line out of data received by said input interface means through saidplurality of lines, said line selection means including a codegenerating means for generating a code whose state is changed insynchronism with a change of said lines; and an output interface meansfor transmitting data received by said line which is selected by theline selection means and said code.
 9. A source controller, comprising:a control means for controlling a plurality of information outputdevices, at least concerning their starting of output; a switching meansfor selecting some one information output device out of said pluralityof information output devices; and a signal generating means foroutputting a signal whose state is changed in synchronism with a pointof time at which said switching means switches the information outputdevice to be selected.
 10. A source controller, comprising: a controlmeans for controlling a plurality of information output devices, atleast concerning their starting of output; a switching means forselecting some one information output device out of said plurality ofinformation output devices; and a signal generating means for decidingcontents of programme associated information inclusive of a code thatchanges its state in synchronism with a point of time at which saidswitching means switches the information output device to be selected,and for generating a signal indicating said decided contents.
 11. A datamultiplex system, comprising: a plurality of information output devices;a source controller; a programme configuration information generatingmeans for generating programme configuration information in accordancewith a signal supplied from said source controller; an encoding meansfor receiving output information from an information output deviceselected by said source controller, and for generating encoded data; amultiplexing means for multiplexing the encoded data generated by saidencoding means and the programme configuration information generated bysaid programme configuration information generating means, and forgenerating multiplex signal; a modulating means for modulating themultiplex signal generated by said multiplexing means; and atransmitting means for broadcasting the multiplex signal modulated bysaid modulating means.
 12. A receiving device for receiving datamultiplex signal, comprising: an extracting means for extracting a musicpiece broadcast end bit and an M/S flag from a multiplex signal, saidmusic piece broadcast end bit being reversed in its logic beingsynchronized with an end of a music piece broadcasted, and said M/S flagindicating music or speech; and an outputting means for outputting asignal indicating a division between music pieces, in synchronism with apoint of time at which said music piece broadcast end bit is reversed inits logic in a state that said M/S flag indicates music.
 13. A receivingdevice for receiving data multiplex signal, comprising: an extractingmeans for extracting an information bit indicating a number of remainingmusic pieces to be broadcasted and an M/S flag indicating music orspeech; a signal generating means for generating a signal that indicatesa value indicated by said information bit, when said M/S flag indicatesmusic.
 14. The receiving device according to claim 12, wherein: saidsignal generating means outputs a signal indicating an end ofbroadcasting a music piece, in synchronism with change of a valueindicated by said information bit.
 15. A system controller forcontrolling a receiving device and recording device which areinterconnected, wherein: said receiving device extracts data to betransmitted and a code indicating an ordinal number from a receivedsignal, said code corresponding to each content element out of a seriesof content elements expressed by said data, and said receiving deviceoutputs said extracted data and code; and said system controllercomprises: an interface means for receiving an operation of designatingan ordinal number corresponding to some one out of the series of contentelements; and a control means for causing the recording device to startto record, when said code indicating the designated ordinal number isinputted.
 16. A recording device for receiving data multiplex signal andrecording contents of said data multiplex signal, comprising: arecording means for recording data; an interface means for receiving aninstruction to start recording; an extracting means for extracting dataexpressing contents and a divisional signal concerning contents of saiddata, from the data multiplex signal received; a buffer memory means forstoring said extracted data and said divisional signal over a certainperiod; a detecting means for detecting a point of time at which a stateof the divisional signal stored in said buffer memory means changes; anda transfer means for supplying data stored in said buffer memory meanssince said detected point of time at which the state of the divisionalsignal changed, to said recording means, when the instruction isreceived by said interface means.
 17. The recording device according toclaim 16, further comprising: a display means for displaying a timeperiod obtained by subtracting a period elapsed from said detected pointof time at which the state of the divisional signal changed from saidcertain period for which said buffer memory means can store the data.